Cellulase and xylanase are in high demand for application in several industrial processes, consequently necessitating the bioprospecting and manipulation of microbes for novel and greater enzyme productivity. This study reports on the optimal conditions for cellulase and xylanase production by a marine bacterial isolate from Nahoon beach sediment, via the classical process of one variable per time. Furthermore, the inducing effect of mono-and polysaccharides on enzyme production was investigated. The 16S rDNA gene sequence analysis clearly assigned the isolate to the genus Streptomyces, and was deposited at the GenBank under the accession number KU171373. Cellulase and xylanase production was optimal at the following conditions: pH 6 and 8, incubation temperature of 40 and 35 • C, and agitation speed of 100 and 150 rpm, respectively. Under optimum conditions, 0.26 U/mL and 18.54 U/mL activities were attained at 60 and 48 h with specific productivity of 205 and 7417 U/g for cellulase and xylanase, respectively. Xylanase production was induced by the entire mono-and polysaccharides tested, while cellulase production was induced by some. The results from this study signify the resourcefulness of the Streptomyces strain for production of cellulase and xylanase of industrial importance.

Fish currently provide 6.7% of all protein consumed by humans globally, nevertheless, aquaculture system has been linked to fish and environmental contamination and disease outbreak. This study aims to isolate, identify, and characterise, bacteria in fish and pond water as well as the antibiotic profile of detected Coliforms. The susceptibility of the isolates was tested using the Kirby-Bauer disc diffusion method on Mueller Hinton agar. A total of forty (40) isolates were isolated from the water samples of which (5) species were Gram Positive bacteria and 35 species of Gram Negative bacteria. The temperature for all ponds ranged from 25°C to 28°C. The mean bacteria count for pond C1 to T2 were 4.9 × 102, 4.9 × 102, 5.4 × 102, 2.5 × 102, 2.2 × 102, and 1.9 × 102 CFU/ml respectively. All isolates were 100% resistant to ceftazidime, cefuroxime and augmentin. More resistance to cefixime (80%) and gentamicin (73.3%) and nitrofurantoin (66.7%) was recorded. However, only 16.6% and 8.3% of the isolates were resistant to ciprofloxacin and ofloxacin respectively. The multiple antimicrobial resistance index (MARI) ranged from 0.5 to 0.9. The water quality parameters (temperature and pH) and the type of bacteria detected in all pond type did not differ significantly. The Multi-drug resistance bacteria detected could be pathogenic to fish and consumers.

Background: Fish currently provide 6.7% of all proteins consumed by humans globally; nevertheless, the aquaculture system has been linked to fish, environmental contamination and disease outbreak. The aim of this study was to determine the bacteriological quality and the antibiotic resistance profile of bacteria from water samples of pond stocked with Tilapia and Catfish in Ile-Ife, Osun State, Nigeria. Objective: To isolate, identify and characterise heterotrophic bacteria and test for the antibiogram of detected Coliforms. Methods: Water samples were collected from ponds stocked with Tilapia and Catfish, and tested for total heterotrophic and coliform bacteria as well as the antibiogram. The susceptibility of the isolates was tested using the Kirby-Bauer disc diffusion method on Mueller Hinton agar. Results: A total of 40 isolates were recovered from the water samples, of which 5 species were Gram positive bacteria representing two genera, and 35 species were Gram negative bacteria representing four genera. The temperature for all ponds ranged from 25°C to 28°C. The mean bacterial count varied from 1.9×104 to 5.4×104 CFU/ml per fish pond. All isolates were 100% resistant to ceftazidime, cefuroxime and augmentin. More resistance to cefixime (80%) and gentamicin (73.3%) and nitrofurantoin (66.7%) was also recorded. However, only 16.6% and 8.3% of the isolates were resistant to ciprofloxacin and ofloxacin, respectively. The multiple antimicrobial resistance index (MARI) ranged from 0.5 to 0.9. The water physicochemical parameters (temperature and pH) and the type of bacteria detected in all pond types did not differ significantly. Conclusion: Fish pond is a reservoir of multi-drug resistant bacteria that could serve as environmental source of drug resistance gene transfer. This calls for effective monitoring and assessment as well as management devices for the protection of community and environmental health.

Production of holocellulase by a newly isolated marine Bacillus species via submerged fermentation technique at varying cultivation conditions was investigated. Enzyme production was optimized by altering one variable per time. Moreover effect of lignocellulosic saccharides in inducing cellulase and xylanase production was also investigated. The 16S ribosomal Deoxyribonucleic Acid (16S rDNA) gene sequence analysis exhibited 98% sequence similarity of the isolate with other Bacillus species in the gene bank and was deposited with the accession number KX524510. Optimal xylanase and cellulase production was attained at pH 7, temperature 30°C and agitation speed of 50 and 150 rpm. Furthermore, maximum xylanase and cellulase production were both achieved at 60 h corresponding to the late stationary growth stage, with activity of 16.6 and 0.061 U mL −1 respectively. Xylanase production was maximally induced by beechwood xylan, xylose and arabinose with activities of 13.59, 8.78 and 1.90 (U mL −1 ) respectively; while cellulase production was induced by carboxymethyl cellulose only and no cellulase activity was detected in the culture supernatant of the other carbon sources tested. Optimization increased cellulase and xylanase yields being 0.006-0.061 and 0.23-16.6 (U mL −1 ) from unoptimized to optimized respectively. The results of the study suggest the bacterial strain to be a proficient producer of cellulase and xylanase with potentials in biotechnological application.